/* $Id: SwingWorker.java 17841 2010-01-12 19:17:52Z linus $ ***************************************************************************** * Copyright (c) 2009 Contributors - see below * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * tfmorris ***************************************************************************** * * Some portions of this file was previously release using the BSD License: */ // Copyright (c) 1996-2007 The Regents of the University of California. All // Rights Reserved. Permission to use, copy, modify, and distribute this // software and its documentation without fee, and without a written // agreement is hereby granted, provided that the above copyright notice // and this paragraph appear in all copies. This software program and // documentation are copyrighted by The Regents of the University of // California. The software program and documentation are supplied "AS // IS", without any accompanying services from The Regents. The Regents // does not warrant that the operation of the program will be // uninterrupted or error-free. The end-user understands that the program // was developed for research purposes and is advised not to rely // exclusively on the program for any reason. IN NO EVENT SHALL THE // UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, // SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, // ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF // THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF // SUCH DAMAGE. THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY // WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF // MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE // PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF // CALIFORNIA HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT, // UPDATES, ENHANCEMENTS, OR MODIFICATIONS. package org.argouml.ui; import java.awt.Cursor; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.SwingUtilities; import javax.swing.Timer; import org.apache.log4j.Logger; import org.argouml.swingext.GlassPane; import org.argouml.taskmgmt.ProgressMonitor; import org.argouml.util.ArgoFrame; /** * This is the 3rd version of SwingWorker (also known as * SwingWorker 3), an abstract class that you subclass to * perform GUI-related work in a dedicated thread. For * instructions on and examples of using this class, see: * * http://java.sun.com/docs/books/tutorial/uiswing/misc/threads.html * * Note that the API changed slightly in the 3rd version: * You must now invoke start() on the SwingWorker after * creating it. */ public abstract class SwingWorker { private static final Logger LOG = Logger.getLogger(SwingWorker.class); private Object value; // see getValue(), setValue() private GlassPane glassPane; private Timer timer; private ProgressMonitor pmw; /** * Class to maintain reference to current worker thread * under separate synchronization control. */ private static class ThreadVar { private Thread thread; ThreadVar(Thread t) { thread = t; } synchronized Thread get() { return thread; } synchronized void clear() { thread = null; } } private ThreadVar threadVar; /** * Get the value produced by the worker thread, or null if it * hasn't been constructed yet. * * @return the value produced by the worker thread */ protected synchronized Object getValue() { return value; } /** * Set the value produced by worker thread */ private synchronized void setValue(Object x) { value = x; } /** * Compute the value to be returned by the <code>get</code> method. * * @param progressMonitor the ProgressMonitorWindow class - this * class shall be registered as a progress listener. * @return the value to be returned */ public abstract Object construct(ProgressMonitor progressMonitor); /** * Instantiate and initialize an instance of ProgressMonitorWindow * * @return an instance of ProgressMonitorWindow */ public abstract ProgressMonitor initProgressMonitorWindow(); /** * This method calls the construct(), * * @return the value to be returned by the <code>get</code> method. */ public Object doConstruct() { activateGlassPane(); pmw = initProgressMonitorWindow(); ArgoFrame.getFrame().setCursor( Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR)); Object retVal = null; //Create a timer. timer = new Timer(25, new TimerListener()); timer.start(); try { retVal = construct(pmw); } catch (Exception exc) { // TODO: This error needs to be reported! LOG.error("Error while loading project: ", exc); } finally { pmw.close(); } return retVal; } /** * The actionPerformed method in this class * is called each time the Timer "goes off". */ class TimerListener implements ActionListener { public void actionPerformed(ActionEvent evt) { if (pmw.isCanceled()) { threadVar.thread.interrupt(); interrupt(); timer.stop(); } } } /** * Activate the capabilities of glasspane */ protected void activateGlassPane() { // Mount the glasspane on the component window GlassPane aPane = GlassPane.mount(ArgoFrame.getFrame(), true); // keep track of the glasspane as an instance variable setGlassPane(aPane); if (getGlassPane() != null) { // Start interception UI interactions getGlassPane().setVisible(true); } } /** * Deactivate the glasspane */ private void deactivateGlassPane() { if (getGlassPane() != null) { // Stop UI interception getGlassPane().setVisible(false); } } /** * Called on the event dispatching thread (not on the worker thread) * after the <code>construct</code> method has returned. */ public void finished() { deactivateGlassPane(); ArgoFrame.getFrame().setCursor(Cursor.getPredefinedCursor( Cursor.DEFAULT_CURSOR)); } /** * Getter method for the glassPange * * @return GlassPane the blocking glassPane */ protected GlassPane getGlassPane() { return glassPane; } /** * Setter method * * @param newGlassPane GlassPane */ protected void setGlassPane(GlassPane newGlassPane) { glassPane = newGlassPane; } /** * A new method that interrupts the worker thread. Call this method * to force the worker to stop what it's doing. */ public void interrupt() { Thread t = threadVar.get(); if (t != null) { t.interrupt(); } threadVar.clear(); } /** * Return the value created by the <code>construct</code> method. * Returns null if either the constructing thread or the current * thread was interrupted before a value was produced. * * @return the value created by the <code>construct</code> method */ public Object get() { while (true) { Thread t = threadVar.get(); if (t == null) { return getValue(); } try { t.join(); } catch (InterruptedException e) { Thread.currentThread().interrupt(); // propagate return null; } } } /** * Construct a worker thread that will call the <code>construct</code> method * and then exit. */ public SwingWorker() { final Runnable doFinished = new Runnable() { public void run() { finished(); } }; Runnable doConstruct = new Runnable() { public void run() { try { setValue(doConstruct()); } finally { threadVar.clear(); } SwingUtilities.invokeLater(doFinished); } }; Thread t = new Thread(doConstruct); threadVar = new ThreadVar(t); } public SwingWorker(String threadName) { this(); threadVar.get().setName(threadName); } /** * Start the worker thread. */ public void start() { Thread t = threadVar.get(); if (t != null) { t.start(); } } }